If various aquatic organisms, e.g., animals such as oysters, mussels and barnacles, and plants such as layer, adhere and propagate on the surfaces of water-contact portions of ships, fishing nets, marine structures such as supply and drainpipes for seawater, etc., appearances of the ships, etc. are marred and functions thereof are sometimes impaired. Especially when such aquatic organisms adhere and propagate on a ship's bottom, surface roughness of the ship's bottom is increased to sometimes induce lowering of velocity of the ship and increase of fuel cost.
In order to prevent such damages, the surfaces of the above substrates are coated with various antifouling coating materials. For the exhibition of antifouling effects, physiologically active substances (e.g., organotin compound) have been added to the antifouling coating materials in the past. However, problems on the safety in the coating working and the environmental safety have been recognized, and development of antifouling coating materials capable of preventing adhesion of aquatic organisms without using such physiologically active substances has been promoted.
For example, in patent literatures 1 and 2, an organopolysiloxane-thio block vinyl copolymer formed from a polyoxyalkylene group-containing vinyl copolymer block and a specific organopolysiloxane-thio block, and an antifouling coating composition containing the copolymer and silicone oil are described.
In a patent literature 3, an antifouling coating material obtained by adding polyether modified silicone oil having HLB of 3 to 12 to a non-silicone based film-forming resin is described.
In a patent literature 4, a copolymer containing both-end (meth)acrylic modified silicon-containing polymerizable monomer units and metal atom-containing polymerizable monomer units containing a divalent metal atom, and a coating composition containing the copolymer are described.
In patent literatures 5 and 6, a polysiloxane/acrylic resin block copolymer having a crosslinked structure due to a given metal and an antifouling coating composition containing the copolymer are described.
In patent literatures 7 and 8, a graft copolymer comprising (meth)acrylic group-containing polyether modified silicone and another polymerizable monomer, and a coating composition containing the copolymer are described.